Friday, November 14, 2014

There are times when you need to capture an event, but you can’t
spare the time to be there every day. If you can place your camera in a secure
location, you can use GBTimelapse to capture the images automatically. It can
start and stop at set times each day and automatically adjust the exposure for
flicker-free capture.

Here’s a behind the scenes look at how I used GBTimelapse to
capture the daily “Wild Turkey Parade“ across our property.

I placed a camera in an upstairs window with a view of the
turkey’s daily route. I used a Bower 24mm manual lens with the aperture constant
at f/5.6 to prevent any aperture flicker and I draped the back of the camera
with a black cloth to block any window reflections.

I needed a wide angle lens to cover the unpredictable turkey
wandering, but the full wide angle image included a bright sky and foreground.

To get the correct exposure in the middle ground, I used
GBTimelapse’ new luminance region option. Instead of calculating the histogram
over the full frame, you can specify an arbitrary sub-rectangle for the
histogram. Here you can see the region I set to eliminate the sky and
foreground. This guaranteed a proper exposure of the middle ground regardless
of how bright the sky was.

Because I was capturing large/fine jpegs with at 5760x3840,
I was able to crop down to 1280x720 in After Effects and pan as the turkeys
wandered across the full frame.

The turkeys start their parade just before dawn, but the
sunrise time changes rapidly in the fall at this latitude. So, I set the
GBTimelapse program to start every day at 25 minutes before dawn and to run for
30 minutes.

My initial exposure at that time before sunrise was about 2
seconds, f/5.6 and ISO 100. Each day was different because of the different
cloud cover and lighting, but GBTimelapse AutoRamp would settle on a good exposure
in just a few frames.

By using bulb mode, I was guaranteed to get smooth exposure
changes with no Tv stepping as the scene brightened by more than 4 f-stops over
the 30-minute period.

I set the GBTimelapse AutoRamp parameters to keep the bulb
time between 1 and 2 seconds. Each time GBTimelapse adjusted the bulb time down
to 1 second, it would halve the ISO and double the bulb time back to 2 seconds.

A 4 second interval with a 2 second exposure gave a nice “180
degree shutter” look to the video instead of the choppy look from a shorter
exposure.

This may not be the most interesting video, but the
techniques I used are very powerful!

For our professional clients...the ability to
run automatically can greatly increase your productivity. You should consider
it the next time you can place a camera in a secure location.

Wednesday, November 12, 2014

Looking to achieve the time-lapse "holy grail" with your motion control gear? You are in luck! GBTimelapse 3.10 has added several features focused on achieving the elusive sunset, sunrise and overnight "holy grail." Read on!

New Master/Slave Modes

GBT version 3.10 adds several new Master/Slave modes.
These new modes enable you to get GBT’s Holy Grail AutoRamp power with
virtually any motion control device!

As an added bonus, GBT 3.10 also...

Adds even greater compatibility
with the eMotimo TB3 Black.

Adds the ability
to synchronize multiple cameras connected on multiple computers (more about this in future posts).

New eMotimo Slave/TB3 mode features

Uses third axis for slider control
(Rhino, Dynamic Perception or any other
stepper).

Uses TB3 joystick setup parameters
for 2 and 3-point moves,

or optionally use GBTimelapse
control panel to setup all parameters for 2 and 3-point moves.